EK Water Blocks EKWB EK-Ekoolant Pastel Blue Concentrate (250mL) Color: Pastel Blue 250mL Concentrate - to be mixed with 750mL of distilled water, yielding 1L of coolant total EK-Ekoolant is a high efficient, non-toxic, anti-corrosion coolant, and biologic growth coolant with a shelf life of 3 years from the date of bottling High quality concentrated pigments Low Electrical Conductivity